My invention relates to an aerating apparatus or fountain for removing or expelling volatile impurities from ground water, especially pressurized ground water.
An aerating apparatus for expelling volatile impurities from ground water and earth through which the ground water flows is known in which the impurities are expelled by generating a partial vacuum in an aeration shaft in the vicinity of the ground water to be purified and by feeding fresh air below the water level in an aeration shaft.
Apparatus of the above-described type has already been described(e.g. in German Open Patent Application No. 36 25 488 of the applicant). In contrast to the conventional process, in which pressurized air is pressed into the earth surrounding the aeration shaft and/or into the ground water collecting in the aeration shaft with considerable energy consumption, in this design air alone is conducted with a partial vacuum formed in the water-free portion of the aeration shaft. It has been shown that with comparatively little vacuum surprisingly large quantities of volatile impurities in the gaseous state can be drawn off and a considerably larger efficiency can be attained than in the above-mentioned conventional process. In the conventional process laminar flows are ruptured by the high pressure employed and vortexes form, which considerably reduce the efficiency of the plant.
The performance of the preceding process is difficult in cases in which pressurized ground water or ground water at a ground water pressure corresponding to an overpressure must be treated. This case can occur especially when mineral water, which frequently stands under an overpressure, must be purified by the aeration shaft.